#include "../server.hpp"
#include <iostream>
#include <fstream>
#include <sys/stat.h>
#include <regex>

#define DEFALT_TIMEOUT 10

std::unordered_map<int, std::string> _statu_mag = {
    {100, "Continue"},
    {101, "Switching Protocol"},
    {102, "Processing"},
    {103, "Early Hints"},
    {200, "OK"},
    {201, "Created"},
    {202, "Accepted"},
    {203, "Non-Authoritative Information"},
    {204, "No Content"},
    {205, "Reset Content"},
    {206, "Partial Content"},
    {207, "Multi-Status"},
    {208, "Already Reported"},
    {226, "IM Used"},
    {300, "Multiple Choice"},
    {301, "Moved Permanently"},
    {302, "Found"},
    {303, "See Other"},
    {304, "Not Modified"},
    {305, "Use Proxy"},
    {306, "unused"},
    {307, "Temporary Redirect"},
    {308, "Permanent Redirect"},
    {400, "Bad Request"},
    {401, "Unauthorized"},
    {402, "Payment Required"},
    {403, "Forbidden"},
    {404, "Not Found"},
    {405, "Method Not Allowed"},
    {406, "Not Acceptable"},
    {407, "Proxy Authentication Required"},
    {408, "Request Timeout"},
    {409, "Conflict"},
    {410, "Gone"},
    {411, "Length Required"},
    {412, "Precondition Failed"},
    {413, "Payload Too Large"},
    {414, "URI Too Long"},
    {415, "Unsupported Media Type"},
    {416, "Range Not Satisfiable"},
    {417, "Expectation Failed"},
    {418, "I'm a teapot"},
    {421, "Misdirected Request"},
    {422, "Unprocessable Entity"},
    {423, "Locked"},
    {424, "Failed Dependency"},
    {425, "Too Early"},
    {426, "Upgrade Required"},
    {428, "Precondition Required"},
    {429, "Too Many Requests"},
    {431, "Request Header Fields Too Large"},
    {451, "Unavailable For Legal Reasons"},
    {501, "Not Implemented"},
    {502, "Bad Gateway"},
    {503, "Service Unavailable"},
    {504, "Gateway Timeout"},
    {505, "HTTP Version Not Supported"},
    {506, "Variant Also Negotiates"},
    {507, "Insufficient Storage"},
    {508, "Loop Detected"},
    {510, "Not Extended"},
    {511, "Network Authentication Required"}
};

std::unordered_map<std::string, std::string> _mime_msg = {
    {".aac", "audio/aac"},
    {".abw", "application/x-abiword"},
    {".arc", "application/x-freearc"},
    {".avi", "video/x-msvideo"},
    {".azw", "application/vnd.amazon.ebook"},
    {".bin", "application/octet-stream"},
    {".bmp", "image/bmp"},
    {".bz", "application/x-bzip"},
    {".bz2", "application/x-bzip2"},
    {".csh", "application/x-csh"},
    {".css", "text/css"},
    {".csv", "text/csv"},
    {".doc", "application/msword"},
    {".docx", "application/vnd.openxmlformatsofficedocument.wordprocessingml.document"},
    {".eot", "application/vnd.ms-fontobject"},
    {".epub", "application/epub+zip"},
    {".gif", "image/gif"},
    {".htm", "text/html"},
    {".html", "text/html"},
    {".ico", "image/vnd.microsoft.icon"},
    {".ics", "text/calendar"},
    {".jar", "application/java-archive"},
    {".jpeg", "image/jpeg"},
    {".jpg", "image/jpeg"},
    {".js", "text/javascript"},
    {".json", "application/json"},
    {".jsonld", "application/ld+json"},
    {".mid", "audio/midi"},
    {".midi", "audio/x-midi"},
    {".mjs", "text/javascript"},
    {".mp3", "audio/mpeg"},
    {".mpeg", "video/mpeg"},
    {".mpkg", "application/vnd.apple.installer+xml"},
    {".odp", "application/vnd.oasis.opendocument.presentation"},
    {".ods", "application/vnd.oasis.opendocument.spreadsheet"},
    {".odt", "application/vnd.oasis.opendocument.text"},
    {".oga", "audio/ogg"},
    {".ogv", "video/ogg"},
    {".ogx", "application/ogg"},
    {".otf", "font/otf"},
    {".png", "image/png"},
    {".pdf", "application/pdf"},
    {".ppt", "application/vnd.ms-powerpoint"},
    {".pptx", "application/vnd.openxmlformatsofficedocument.presentationml.presentation"},
    {".rar", "application/x-rar-compressed"},
    {".rtf", "application/rtf"},
    {".sh", "application/x-sh"},
    {".svg", "image/svg+xml"},
    {".swf", "application/x-shockwave-flash"},
    {".tar", "application/x-tar"},
    {".tif", "image/tiff"},
    {".tiff", "image/tiff"},
    {".ttf", "font/ttf"},
    {".txt", "text/plain"},
    {".vsd", "application/vnd.visio"},
    {".wav", "audio/wav"},
    {".weba", "audio/webm"},
    {".webm", "video/webm"},
    {".webp", "image/webp"},
    {".woff", "font/woff"},
    {".woff2", "font/woff2"},
    {".xhtml", "application/xhtml+xml"},
    {".xls", "application/vnd.ms-excel"},
    {".xlsx", "application/vnd.openxmlformatsofficedocument.spreadsheetml.sheet"},
    {".xml", "application/xml"},
    {".xul", "application/vnd.mozilla.xul+xml"},
    {".zip", "application/zip"},
    {".3gp", "video/3gpp"},
    {".3g2", "video/3gpp2"},
    {".7z", "application/x-7z-compressed"}
};

class Util{
    public:
        //字符串分割函数,将src字符串按照sep字符串进行分割，得到的各个字串放到arry中，最终返回字串的数量
        //abd,def,lnm
        static size_t Split(const std::string &src, const std::string &sep, std::vector<std::string> *arry){
            size_t offset = 0;
            while(offset < src.size()){
                size_t pos = src.find(sep, offset);//在src字符串偏移量offest处，开始向后查找sep字符/字串，返回查找到的位置
                if(pos == std::string::npos){//没有找到特点字符
                    //将剩余的部分当作一个字串，放入arry中
                    if(pos == src.size()) break;
                    arry->push_back(src.substr(offset));
                    return arry->size();
                }
                if(pos == offset) {
                    offset = pos + sep.size();
                    continue;//当前字串是一个空的没有内容
                }
                arry->push_back(src.substr(offset, pos - offset));
                offset = pos + sep.size();
            }
            return arry->size();
        }
        //读取文件所有内容,将读取的内容放到buffer中
        static bool ReadFile(const std::string &filename, std::string &buf){
            std::ifstream ifs(filename, std::ios::binary);
            if(ifs.is_open() == false){
                ERR_LOG("open %s file failed", filename.c_str());
                return false;
            }
            size_t fsize = 0;
            ifs.seekg(0, ifs.end);//跳转读写位置到末尾
            fsize = ifs.tellg();//获取当前读写位置相对于起始位置的偏移量，从末尾偏移刚好就是文件大小
            ifs.seekg(0, ifs.beg);//跳转到起始位置
            buf.resize(fsize);//开辟文件大小的空间
            ifs.read(&buf[0], fsize);
            if(ifs.good() == false){
                ERR_LOG("read %s failed", filename.c_str());
                ifs.close();
                return false;
            }
            ifs.close();
            return true;
        }
        //向文件写入数据
        static bool WriteFile(const std::string &filename, const std::string &buf){
            std::ofstream ofs(filename, std::ios::binary | std::ios::trunc);
            if(ofs.is_open() == false){
                ERR_LOG("open %s file failed", filename.c_str());
                return false;
            }
            ofs.write(buf.c_str(), buf.size());
            if(ofs.good() == false){
                ERR_LOG("write %s failed", filename.c_str());
                ofs.close();
                return false;
            }
            ofs.close();
            return false;
        }
        //URL编码，避免URL中资源路径与查询字符串的特殊字符与HTTP请求中特殊字符产生歧义
        //编码格式：将特殊字符中的ascii值，转换为两个16进制字符，前缀%  C++ -> C%2B%2B
        //不编码的特殊字符：RFC3986规定：.-_~以及字母和数字属于绝对不编码字符
        //RFC3986文档规定，编码格式 %HH
        //W3C文档中规定，查询字符串中的空格需要被转换为 + ，解码就是+转空格
        static std::string UrlEncode(const std::string url, bool convert_space_to_plus){
            std::string res;
            for(auto &c : url){
                if(c == '.' || c == '-' || c == '_' || c == '~' || isalnum(c) == true){
                    res += c;
                    continue;
                }
                if(c == ' ' && convert_space_to_plus == true){
                    res += '+';
                    continue;
                }
                //剩下的字符都是需要编码为%HH格式
                char tmp[4] = {0};
                sprintf(tmp, "%%%02X", c);
                res += tmp;
            }
            return res;
        }
        static char HEXTOI(char c){
            if(c >= '0' && c <= '9'){
                return c - '0';
            }else if(c >= 'a' && c <= 'z'){
                return c - 'a' + 10;
            }else if(c >= 'A' && c <= 'Z'){
                return c - 'A' + 10;
            }
            return -1;
        }
        //URL解码
        static std::string UrlDecode(const std::string url, bool convert_space_to_plus){
            //遇到了%，则将紧随其后的2个字符转换成数字，第一个数字左移4位，然后加上第二个数字 + -> 2b
            std::string res;
            for(int i = 0; i < url.size(); i++){
                if(url[i] == '+' && convert_space_to_plus == true){
                    res += ' ';
                    continue;
                }
                if(url[i] == '%' && (i + 2) < url.size()){
                    char v1 = HEXTOI(url[i + 1]);
                    char v2 = HEXTOI(url[i + 2]);
                    char v = (v1 << 4) + v2;
                    res += v;
                    i += 2;
                    continue;
                }
                res += url[i];
            }
            return res;
        }
        //响应状态码的描述信息获取
        static std::string StatuDesc(int statu){
            
            auto it = _statu_mag.find(statu);
            if(it != _statu_mag.end()){
                return it->second;
            }
            return "Unknow";
        }
        //根据文件后缀名获取文件mime
        static std::string ExtMime(const std::string &filename){
            
            // a.b.txt  先获取文件扩展名
            size_t pos = filename.find_last_of('.');
            if(pos == std::string::npos){
                return "application/octet-stream";
            }
            //根据扩展名获取mime
            std::string ext = filename.substr(pos);
            auto it = _mime_msg.find(ext);
            if(it == _mime_msg.end()){
                return "application/octet-stream";
            }
            return it->second;
        }
        //判断文件是否是一个目录
        static bool IsDirectory(const std::string &filename){
            struct stat st;
            int ret = stat(filename.c_str(), &st);
            if(ret < 0){
                return false;
            }
            return S_ISDIR(st.st_mode);
        }
        //判断一个文件是否是一个普通文件
        static bool IsRegular(const std::string &filename){
            struct stat st;
            int ret = stat(filename.c_str(), &st);
            if(ret < 0){
                return false;
            }
            return S_ISREG(st.st_mode);
        }
        //http请求的资源路径有效性判断
        // /index.html  --- 前边的/叫做相对根目录，映射的是某个服务器的子目录
        //想表达的意思就是客户端只能请求相对根目录中的资源，其他地方的资源不予理会
        // /../login   这个路径中的..会让路径的查找跑到相对根目录之外，这是不合理的，不安全的
        static bool ValidPath(const std::string &path){
            //思想 ： 按照/进行路径分割，根据有多少子目录，计算目录深度，有多少层，深度不能小于0
            int level = 0;
            std::vector<std::string> subdir;
            Split(path, "/", &subdir);
            for(auto &dir : subdir){
                if(dir == ".."){
                    level--; //任意一层走出相对根目录就认为有问题
                    if(level < 0){
                        return false;
                    }
                }
                level++;
            }
            return true;
        }
};


class HttpRequest{
    public:
        std::string _method;//请求方法
        std::string _path;//资源路径
        std::string _version;//协议版本
        std::string _body;//请求正文
        std::smatch _matches;//资源路径正则提取数据
        std::unordered_map<std::string, std::string> _headers;//头部字段
        std::unordered_map<std::string, std::string> _params;//查询字符串
    public:
        HttpRequest():_version("HTTP/1.1") {}
        void ReSet(){
            _method.clear();
            _path.clear();
            _version = "HTTP/1.1";
            _body.clear();
            std::smatch match;
            _matches.swap(match);
            _headers.clear();
            _params.clear();
        }
        //插入头部字段
        void SetHeader(const std::string &key, const std::string &val){
            _headers.insert(std::make_pair(key, val));
        }
        //判断是否存在指定头部字段
        bool HasHeader(const std::string &key) const {
            auto it = _headers.find(key);
            if(it == _headers.end()){
                return false;
            }
            return true;
        }
        //获取指定头部字段的值
        std::string GetHeader(const std::string &key) const {
            auto it = _headers.find(key);
            if(it == _headers.end()){
                return "";
            }
            return it->second;
        }
        //插入查询字符串
        void SetParam(std::string &key, std::string &val){
            _params.insert(std::make_pair(key, val));
        }
        //判断是否有某个指定的查询字符串
        bool HasParam(std::string &key){
            auto it = _params.find(key);
            if(it == _params.end()){
                return false;
            }
            return true;
        }
        //获取指定的查询字符串
        std::string GetParam(std::string &key){
            auto it = _params.find(key);
            if(it == _params.end()){
                return "";
            }
            return it->second;
        }
        //获取正文长度
        size_t ContentLength(){
            // Content-Length:1234\r\n
            bool ret = HasHeader("Content-Length");
            if(ret == false){
                return 0;
            }
            std::string clen = GetHeader("Content-Length");
            return std::stol(clen);
        }
        //判断是否是短链接
        bool Close() const {
            //没有Connection字段，或者有Connection字段但是值是close就是短链接，否则就是长连接
            
            if(HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive"){
                return false;
            }
            return true;
        }
};

class HttpResponse{
    public:
        int _statu;
        bool _redirect_flag;
        std::string _body;
        std::string _redirect_url;
        std::unordered_map<std::string, std::string> _headers;
    public:
        HttpResponse(): _redirect_flag(false), _statu(200){}
        HttpResponse(int statu): _redirect_flag(false), _statu(statu){}
        void ReSet(){
            _statu = 200;
            _redirect_flag = false;
            _body.clear();
            _redirect_url.clear();
            _headers.clear();
        }
        void SetHeader(const std::string &key, const std::string &val){
            _headers.insert(std::make_pair(key, val));
        }
        //判断是否存在指定头部字段
        bool HasHeader(const std::string &key) const {
            auto it = _headers.find(key);
            if(it == _headers.end()){
                return false;
            }
            return true;
        }
        //获取指定头部字段的值
        std::string GetHeader(const std::string &key){
            auto it = _headers.find(key);
            if(it == _headers.end()){
                return "";
            }
            return it->second;
        }
        void SetContent(const std::string &body, const std::string type = "text/html"){
            _body = body;
            SetHeader("Content-Type", type);
        }
        void SetRedirect(const std::string &url, int statu = 302){
            _statu = statu;
            _redirect_flag = true;
            _redirect_url = url;
        }
        bool Close(){
            //没有Connection字段，或者有Connection字段但是值是close就是短链接，否则就是长连接
            if(HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive"){
                return false;
            }
            return true;
        }
};

typedef enum {
    RECV_HTTP_ERROR,
    RECV_HTTP_LINE,
    RECV_HTTP_HEAD,
    RECV_HTTP_BODY,
    RECV_HTTP_OVER
}HttpRecvStatu;
#define MAX_LINE 8192
class HttpContext{
    private:
        int _resp_statu;//响应状态码
        HttpRecvStatu _recv_statu;//当前接收及解析的阶段状态
        HttpRequest _request;//已经解析得到的请求信息
        bool ParseHttpLine(const std::string &line){
            std::smatch matches;
            std::regex e("(GET|HEAD|POST|PUT|DELETE) ([^?]*)(?:\\?(.*))? (HTTP/1\\.[01])(?:\n|\r\n)?", std::regex::icase);
            bool ret = std::regex_match(line, matches, e);
            if(ret == false){
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400;//bad request
                return false;
            }
            //0 :GET /bitejiuyeke/login?user=xiaoming&pass=123123 HTTP/1.1
            //1 : GET
            //2 :/bitejiuyeke/login
            //3 :user=xiaoming&pass=123123
            //4 :HTTP/1.1
            _request._method = matches[1];
            std::transform(_request._method.begin(), _request._method.end(), _request._method.begin(), ::toupper);
            //资源路径的获取，需要进行URL解码操作，但是不需要+转空格
            _request._path = Util::UrlDecode(matches[2], false);
            //协议版本的获取
            _request._version = matches[4];
            //查询字符串的获取与处理
            std::vector<std::string> query_string_arry;
            std::string query_string = matches[3];
            //查询字符串的格式 key=val&key=val....，先以&符号进行分割，得到各个字串
            Util::Split(query_string, "&", &query_string_arry);
            //针对各个字串，以=符号进行分割，得到key和val，得到之后需要进行URL解码
            for(auto &str : query_string_arry){
                size_t pos = str.find("=");
                if(pos == std::string::npos){
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 400;//bad request
                    return false;
                }
                std::string key = Util::UrlDecode(str.substr(0, pos), true);
                std::string val = Util::UrlDecode(str.substr(pos + 1), true);
                _request.SetParam(key, val);
            }
            return true;
        }
    private:
        //接收请求行接口
        bool RecvHttpLine(Buffer *buf){
            if(_recv_statu != RECV_HTTP_LINE) return false;
            // 1.获取一行数据,带有末尾的换行符
            std::string line = buf->GetLineAndPop();
            // 2.需要考虑的一些要素，缓冲区中的数据不足一行，获取的一行数据超大
            if(line.size() == 0){
                //缓冲区的数据不足一行 则需要判断缓冲区的可读数据长度，如果很长了都不足一行，这是有问题的
                if(buf->ReadAbleSize() > MAX_LINE){
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414;//uri too long
                    return false;
                }
                //缓冲区中数据不足一行，但是也不多，就等等新数据的到来
                return true;
            }
            if(line.size() > MAX_LINE){
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414;//uri too long
                return false;
            }
            bool ret = ParseHttpLine(line);
            if(ret == false){
                return false;
            }
            //头部处理完毕，进入头部获取阶段
            _recv_statu = RECV_HTTP_HEAD;
            return true;
        }
        bool RecvHttpHead(Buffer *buf){
            if(_recv_statu != RECV_HTTP_HEAD) return false;
            while(1){
                std::string line = buf->GetLineAndPop();
                //一行一行取出数据直到遇到空行为止,头部的格式 key: val\r\nkey: val\r\n
                if(line.size() == 0){
                    //缓冲区的数据不足一行 则需要判断缓冲区的可读数据长度，如果很长了都不足一行，这是有问题的
                    if(buf->ReadAbleSize() > MAX_LINE){
                        _recv_statu = RECV_HTTP_ERROR;
                        _resp_statu = 414;//uri too long
                        return false;
                    }
                    //缓冲区中数据不足一行，但是也不多，就等等新数据的到来
                    return true;
                }
                if(line.size() > MAX_LINE){
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414;//uri too long
                    return false;
                }
                if(line == "\n" || line == "\r\n"){
                    break;
                }
                bool ret = ParseHttpHead(line);
                if(ret == false){
                    return false;
                }
            }
            //头部处理完毕，进入正文获取阶段
            _recv_statu = RECV_HTTP_BODY;
            return true;
        }
        bool ParseHttpHead(std::string &line){
            // key: val\r\nkey: val\r\n
            if(line.back() == '\n') line.pop_back();//去掉末尾的换行符
            if(line.back() == '\r') line.pop_back();//去掉末尾的回车字符
            size_t pos = line.find(": ");
            if(pos == std::string::npos){
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400;//bad request
                return false;
            }
            std::string key = line.substr(0, pos);
            std::string val = line.substr(pos + 2);
            _request.SetHeader(key, val);
            return true;
        }
        bool RecvHttpBody(Buffer *buf){
            if(_recv_statu != RECV_HTTP_BODY) return false;
            //1.获取正文长度
            size_t context_length = _request.ContentLength();
            if(context_length == 0){
                //没有正文，则请求接收解析完毕
                _recv_statu = RECV_HTTP_OVER;
                return true;
            }
            //2.当前已经接收了多少正文 ,其实就是往 _request._body 中放了多少数据
            size_t real_len = context_length - _request._body.size();//实际还需要接收的正文长度
            //3.接收正文放到body中，但是也要考虑当前缓冲区的数据是否是全部正文

            //3.1缓冲区中数据包含了当前请求的所有正文，则取出所需的数据
            if(buf->ReadAbleSize() >= real_len){
                _request._body.append(buf->ReadPosition(), real_len);
                buf->MoveReadOffset(real_len);
                _recv_statu = RECV_HTTP_OVER;
                return true;
            }
            //3.2缓冲区中的数据无法满足当前正文的需要，数据不足，取出数据，然后新数据到来
            _request._body.append(buf->ReadPosition(), buf->ReadAbleSize());
            buf->MoveReadOffset(buf->ReadAbleSize());
            return true;
        }
    public:
        HttpContext(): _resp_statu(200), _recv_statu(RECV_HTTP_LINE) {}
        int ResponseStatu(){
            return _resp_statu;
        }
        void ReSet(){
            _resp_statu = 200;
            _recv_statu = RECV_HTTP_LINE;
            _request.ReSet();
        }
        HttpRecvStatu RecvStatu(){
            return _recv_statu;
        }
        HttpRequest &Request(){
            return _request;
        }
        //接收并解析http请求
        void RecvHttpRequest(Buffer *buf){
            //不同的状态 做不同的事情，但是这里不要break，因为处理完请求行后，应该立即处理头部，而不是推出等待新数据
            switch(_recv_statu){
                case RECV_HTTP_LINE: RecvHttpLine(buf);
                case RECV_HTTP_HEAD: RecvHttpHead(buf);
                case RECV_HTTP_BODY: RecvHttpBody(buf);
            }
            return;
        }
};


class HttpServer{
    private:
        using Handler = std::function<void(const HttpRequest &, HttpResponse *)>;
        using Handlers = std::vector<std::pair<std::regex, Handler>>;
        Handlers _get_route;
        Handlers _post_route;
        Handlers _put_route;
        Handlers _delete_route;
        std::string _basedir;//静态资源目录
        TcpServer _server;
    private:
        void ErrorHandler(const HttpRequest &req, HttpResponse *rsp){
            //1.组织一个错误展示页面
            std::string body;
            body += "<html>";
            body += "<head>";
            body += "<meta http-equiv='content-Type' content='text/html;charset=utf-8'>";
            body += "</head>";
            body += "<body>";
            body += "<h1>";
            body += std::to_string(rsp->_statu);
            body += " ";
            body += Util::StatuDesc(rsp->_statu);
            body += "/h1";
            body += "/body";
            body += "/html";
            //2.将页面数据当作响应正文放入rsp中
            rsp->SetContent(body, "text/html");
        }
        //将HttpReponse中的要素按照http协议格式进行组织，发送
        void WriteReponse(const PtrConnection &conn, const HttpRequest &req, HttpResponse &rsp){
            //1.先完善头部字段
            if(req.Close() == true){
                // DBG_LOG("CONNECTION IS CLOSE");
                rsp.SetHeader("Connection", "close");
            }else{
                // DBG_LOG("CONNECTION IS KEEP-ALIVE");
                rsp.SetHeader("Connection", "keep-alive");
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Length") == false){
                rsp.SetHeader("Content-Length", std::to_string(rsp._body.size()));
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Type") == false){
                rsp.SetHeader("Content-Type", "application/octet-stream");
            }
            if(rsp._redirect_flag == true){
                rsp.SetHeader("Location", rsp._redirect_url);
            }
            //2.将rsp中的要素，按照http协议格式进行组织
            std::stringstream rsp_str;
            rsp_str << req._version << " " << std::to_string(rsp._statu) << " " << Util::StatuDesc(rsp._statu) << "\r\n";
            for(auto &head : rsp._headers){
                rsp_str << head.first << ": " << head.second << "\r\n";
            }
            rsp_str << "\r\n";
            rsp_str << rsp._body;
            //3.发送数据
            conn->Send(rsp_str.str().c_str(), rsp_str.str().size());
        }
        //判断一个请求是否是一个静态资源请求
        bool IsFileHandler(const HttpRequest &req){
            //1.必须设置了静态资源根目录
            if(_basedir.empty()){
                return false;
            }
            //2.请求方法，必须是GET或者HEAD请求方法
            if(req._method != "GET" && req._method != "HEAD"){
                return false;
            }
            //3.请求的资源路径必须是一个合法路径
            if(Util::ValidPath(req._path) == false){
                return false;
            }
            //4.请求的资源必须存在,且是一个普通文件
            //有一种请求比较特殊 --- 纯粹的目录：/, /image/  这种情况给后边默认追加一个 index.html
            // index.html   /image/a.png
            //不要忘了前缀的相对根目录，也就是讲请求路径转化为实际存在的路径  /image/a.png  ->    ./wwwroot/image/a.png
            std::string req_path = _basedir + req._path;//为了避免直接修改请求资源路径，因此定义一个临时对象
            if(req._path.back() == '/'){
                req_path += "index.html";
            }
            if(Util::IsRegular(req_path) == false){
                return false;
            }
            return true;
        }
        //静态资源请求处理 --- 将静态资源文件的数据读取出来，放到rsp的_body中，并设置mime
        void FileHandler(const HttpRequest &req, HttpResponse *rsp){
            std::string req_path = _basedir + req._path;//为了避免直接修改请求资源路径，因此定义一个临时对象
            if(req._path.back() == '/'){
                req_path += "index.html";
            }
            bool ret = Util::ReadFile(req_path, rsp->_body);
            if(ret == false){
                return;
            }
            std::string mime = Util::ExtMime(req_path);
            rsp->SetHeader("Content-Type", mime);
            return;
        }
        //功能性请求的分类处理
        void Dispatcher(HttpRequest &req, HttpResponse *rsp, Handlers &handlers){
            //在对应请求方法的路由表中，查找是否含有对应资源请求的处理函数，有则调用，没有则发挥404
            //思想：路由表存储的是键值对 -- 正则表达式 & 处理函数
            //使用正则表达式，对请求的资源路径进行正则匹配，匹配成功就使用对应函数进行处理
            // /numbers/\d+      /numbers/12345
            for(auto &handler : handlers){
                const std::regex &re = handler.first;
                const Handler &functor = handler.second;
                bool ret = std::regex_match(req._path, req._matches, re);
                if(ret == false){
                    continue;
                }
                return functor(req, rsp);//传入请求信息，和空的rsp，执行处理函数
            }
            rsp->_statu = 404;
        }
        //路由匹配
        void Route(HttpRequest &req, HttpResponse *rsp){
            //1.对请求进行分辨，是一个静态资源请求，还是一个功能性请求
            //静态资源请求，则进行静态资源请求的处理
            //功能性请求，则需要通过几个请求路由表来确定是否有处理函数
            //既不是静态资源请求，也没有设置对应的功能性请求处理函数，就返回405
            //GET, HEAD 都默认先认为是静态资源请求
            if(IsFileHandler(req) == true){
                //是一个静态资源请求,z则进行静态资源请求的处理
                return FileHandler(req, rsp);
            }
            if(req._method == "GET" || req._method == "HEAD"){
                return Dispatcher(req, rsp, _get_route);
            }else if(req._method == "POST"){
                return Dispatcher(req, rsp, _post_route);
            }else if(req._method == "PUT"){
                return Dispatcher(req, rsp, _put_route);
            }else if(req._method == "DELETE"){
                return Dispatcher(req, rsp, _delete_route);
            }
            rsp->_statu = 405;//not found
            return;
        }
        //设置上下文
        void OnConnected(const PtrConnection &conn){
            conn->SetContext(HttpContext());
            DBG_LOG("NEW CONNECTION %p", conn.get());
        }   
        //缓冲区数据解析+处理
        void OnMessage(const PtrConnection &conn, Buffer *buf){
            while(buf->ReadAbleSize()){
                    //1.获取上下文
                HttpContext *context = conn->GetContext()->get<HttpContext>();
                //2.通过上下文对缓冲区数据进行解析，得到httprequest对象
                //  1.如果缓冲区的数据解析出错，就直接响应回复出错响应
                //  2.如果解析正常，且请求已经获取完毕，才开始去进行处理
                context->RecvHttpRequest(buf);
                HttpRequest &req = context->Request();
                HttpResponse rsp(context->ResponseStatu());
                if(context->ResponseStatu() >= 400){
                    //进行错误响应，关闭连接
                    ErrorHandler(req, &rsp);//填充一个错误显示页面数据到rsp中
                    WriteReponse(conn, req, rsp);//组织响应发送给客户端
                    context->ReSet();
                    buf->MoveReadOffset(buf->ReadAbleSize());//出错了就把缓冲区数据清空
                    conn->Shutdown();
                    return;
                }
                if(context->RecvStatu() != RECV_HTTP_OVER){
                    //当前请求还没有接收完整,则推出，等新数据到来再重新继续处理
                    return;
                }
                //3.请求路由 + 业务处理
                Route(req, &rsp);
                //4.对httpresponse进行组织发送
                // DBG_LOG("%s", rsp._body.c_str());
                WriteReponse(conn, req, rsp);
                //5.重置上下文
                context->ReSet();
                //6.根据长短连接判断是否关闭连接或者继续处理
                if(rsp.Close() == true){
                    conn->Shutdown();//短链接则直接关闭
                }
            }
            return;
        }
    public:
        HttpServer(int port, int timeout = DEFALT_TIMEOUT): _server(port){
            _server.EnableInactiveRelease(timeout);
            _server.SetConnectedCallback(std::bind(&HttpServer::OnConnected, this, std::placeholders::_1));
            _server.SetMessageCallback(std::bind(&HttpServer::OnMessage, this, std::placeholders::_1, std::placeholders::_2));
        }
        void SetBaseDir(const std::string &path){
            assert(Util::IsDirectory(path) == true);
            _basedir = path;
        }
        //设置/添加 请求（请求的正则表达）与处理函数的映射关系
        void Get(const std::string &pattern, const Handler &handler){
            _get_route.push_back(std::make_pair(std::regex(pattern), handler));
        }
        void Post(const std::string &pattern, const Handler &handler){
            _post_route.push_back(std::make_pair(std::regex(pattern), handler));
        }
        void Put(const std::string &pattern, const Handler &handler){
            _put_route.push_back(std::make_pair(std::regex(pattern), handler));

        }
        void Delete(const std::string &pattern, const Handler &handler){
            _delete_route.push_back(std::make_pair(std::regex(pattern), handler));
        }
        void SetThreadCount(int count){
            _server.SetThreadCount(count);
        }
        void Listen(){
            _server.Strat();
        }
};